Central circuit arrangement for motor vehicles

ABSTRACT

A central circuit arrangement for motor vehicles for central connection of electrical components such as fuses, switchgear, cable harnesses, electronic control units for electrical consumers and similar, comprises a layered conductor packet consisting of flat printed circuit boards superimposed in various planes and mutually separated by insulating boards. In order to establish a large number of different printed circuit board circuits separately and selectively in accordance with the relevant requirements, an electric distributing board (10) is inserted between two neighboring insulating boards (9, 11). Pin strips (21) for making contact with the printed circuit boards (8, 12) adjacent to the insulating boards (9, 11) are mounted on the distributing board (10). A strip conductor (25) with a free connection (26) is associated with each pin (22) of each pin strip (21). A plurality of other separate strip conductors (27) with at least two connections (28) are provided on the distributing board (10). The connections (26, 28) of the strip conductors (25, 27) can be selectively connected with straps ( 29) of appropriate height and possibly different design.

BACKGROUND OF THE INVENTION

The invention relates to a central circuit arrangement for motorvehicles for the central connection of electrical components, such asfuses, switching devices, electronic controls for electrical loads andthe like, and including a plate-like layered packet of conductors whichis composed of flat printed circuit boards that are stacked on top ofone another in different planes and are separated from one another byinsulating plates.

Such a central circuit arrangement essentially performs a distributingfunction in order to supply the electrical loads of the motor vehicle,such as, for example, lights, windshield wipers, blinkers and the like,with electrical voltage by way of conductor strands and wiringharnesses, so as to monitor the operational readiness of the loads,detect and indicate possible faults and, if necessary, interrupt faultycurrent paths. The actuation of the electrical loads is here effected byway of switching devices which are plugged in on the upper face of thecentral circuit arrangement as are the fuses for the load circuits. Thesocket pins engage in pin sockets attached to the uppermost flat circuitboard of the central circuit arrangement. The wiring harnesses are herecontacted on the underside of the central circuit arrangement by way ofplug-in connectors. The plugged-in switching devices usually include anelectronic control circuit with which the respectively associatedelectrical load is controlled.

The actual switching process for switching the load in and out iseffected by means of a relay provided in the switching device. On thebasis of the structural and manufacturing technology design of the flatprinted circuit boards and the plug-in sockets, the central circuitarrangement is rigidly fixed with respect to its distributor functionand can be set or adapted for different requirements only atabove-average expense. Different configurations of flat printed circuitboard circuitry can be realized only by means of particularlycost-intensive retooling which is not economically justified,particularly where small series are involved.

To overcome this drawback, DE-OS 3,525,085 already discloses a centralcircuit arrangement which includes a packet of conductors that arearranged on flat printed circuit boards which are stacked on top of oneanother in different planes and separated from one another by insulatingplates. They are provided with plug-in sockets to receive plug-inportions disposed at components, with at least one conductor beingdisposed at at least one of the plug-in sockets so as to project beyondthe conductor packet at at least one side thereof and to be selectivelyconnected to at least one of the conductors of the insulated, stacked,flat printed circuit boards by way of a conductive bridge disposed onthe side of the conductor packet. Since the conductors project laterallyfrom the conductor packet, on the one hand, the number of possiblecircuit connections is greatly limited because of the amount of spaceavailable and, on the other hand, it is not possible to establish adirect electrical connection between opposing conductors that projectfrom the conductor packet. Moreover, the known central circuitarrangement requires a conductor packet that is composed of a relativelylarge number of flat printed circuit boards and insulating platesbecause many free, unoccupied flat printed circuit board current pathsare required to permit electrical connections to be made between onelong side of the conductor packet and the other long side of theconductor packet.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a central circuitarrangement of the above-mentioned type with which, corresponding torespective requirements, a large number of different flat circuit boardcircuits can selectively be individually fixed by simple means,requiring, however, the least possible number of individual layers, i.e.flat printed circuit boards and insulating plates.

This is accomplished by the invention in that an electrical distributorplate with attached pin strips for contacting the flat circuit boardsadjacent to the insulating plates is disposed between two adjacentinsulating plates, with each pin of each pin strip having an associatedconductor path and a free terminal; and a plurality of further, separateconductor paths having at least two terminals are provided on thedistributor plate; with the terminals of the conductor paths beingselectively connectable by way of straps which, if required, havedifferent height configurations.

The selective connection of the many terminals on the distributor plateby way of the straps eliminates the need for expensive retooling fordifferent flat printed circuit board configurations in order to adaptthem individually to the various requirements for the realization of amultitude of differently configured load circuits. This enables the mostvaried circuits for the different requirements to be created in thefactory simply by changing the placement of the straps. Additionally,the central circuit arrangement according to the invention ensures acompact combination of all current paths in a conductor packet composedof only a few plates. To further increase the number of selectivelyestablishable circuits, an advantageous feature of the inventionprovides that the terminals of the conductor paths on the distributorplate are selectively connectable by way of straps projecting laterallyfrom the conductor packet with the terminals of the insulated, stacked,flat printed circuit boards.

In order to reliably prevent a short circuit between adjacent straps, anadvantageous modification of the subject matter of the inventionprovides that the straps are coated with an insulating lacquer.

According to a further feature of the solution according to theinvention, each strap includes two plug-in components which are angledaway from a base member and are provided with a pinched portion, withthe distance of the pinched portion from the free end of each plug-incomponent being slightly larger than the thickness of the distributorplate and the flat printed circuit boards, respectively. In this way,installation of the straps is considerably simplified since the plug-incomponents of the straps can be inserted into the terminals only untilthey reach the pinched portions. Advisably, according to requirements,the basic member of the straps is bent so that it is disposed indifferent planes.

The conductor paths of the distributor plate may be a drawback if theircopper coating comes loose during the connection with the straps,particularly during laser welding, so that a reliable contact is nolonger ensured. Moreover, the relatively slight thickness of the coppercoating on the conductor paths not always presents a sufficient crosssection for current flow. Therefore, in an advantageous alternativeembodiment of the subject matter of the invention, the pin strips arereplaced by rows of pins and the conductor paths and their freeterminals are replaced by contact sockets which are inserted intocorresponding perforations of the distributor plate. The passage bore ofthe contact sockets in each case receives the free ends of severalassociated straps or the pin of a row of pins as well as the free end ofa strap or the free ends of several associated straps. This measureprevents damage to the contact socket, which could lead to a weakeningof the cross section, during laser welding of the parts to be connectedto one another, thus resulting in a reliable current transfer betweenthese components. Moreover, the strength of the contact socket providesa sufficient cross section for current flow. Thus an exact currenttransfer is realized.

To realize a reliable fixation of the contact sockets in the distributorplate, every contact socket is preferably composed of a sleeve providedwith a continuous flange at its end and inserted in a press fit into theperforation in the distributor plate, with the flange resting on theupper face of the distributor plate.

In an advantageous modification of the subject matter of the invention,the sleeve of the contact socket is provided with constrictions betweenwhich are arranged the free ends of the straps and possibly the pin of arow of pins. In a simple manner, this results in predeterminedpositioning of the components to be received by the sleeve.

In order to realize a compact structure, a further advantageous featureof the invention configures the sleeve of the contact socket and itsconstrictions in such a manner that the free ends of the straps insertedtherein and possibly the pin of a row of pins laterally contact oneanother.

In an alternative embodiment of the invention, each contact socket isconfigured as tubular rivet which accommodates the ends of the strapsand possibly the pin of a row of pins inserted therein so that theylaterally contact one another. In this way, it is possible to employ acommercially available component.

In order to ensure a firm seat of the tubular rivet in the distributorplate, the head of the tubular rivet is advisably supported on the upperside of the distributor plate and the base of the tubular rivet iscaulked to the underside of the distributor plate by way of threeprojections that are spaced at 180° relative to one another.

Additionally it is preferably provided that components such asresistors, capacitors, transistors, microprocessors, of the electroniccontrols for the various electrical loads of the motor vehicle arearranged on the distributor plate separated from the flat plug-in fusesand switching devices disposed on a carrier plate associated with theupper flat printed circuit board of the conductor packet and areconnected with the terminals on the distributor plate by way ofconductor paths. In this way, the electronic controls for the electricalloads can be produced easily and cost-effectively on the distributorplate so that the switching devices to be plugged into the carrier platecan also be manufactured more easily and economically since in mostcases uniform mass produced series equipped, for example, only with onerelay, can be realized.

To permit a compact and economical combination of several differentelectronic controls for actuating the various electrical loads of themotor vehicle, a further advantageous embodiment of the inventionprovides that the electronic controls for the various electrical loadsof the motor vehicle ar centrally combined in a microcomputer on thedistributor plate. This microcomputer includes at least onemicroprocessor in the form an an electronic computer and at least oneprogram memory as well as at least one input/output unit and associatedperipherals. Additionally, the combination in a microcomputer providesthe advantage that the most varied control functions can be considerablybroadened in the smallest possible space.

Moreover, plain connectors for the connection of wiring harnesses andextending through the bottom of a housing accommodating the conductorpacket and the carrier plate are advisably provided in an area definedby a collar shaped to the housing bottom. In this case it is preferredthat the housing is closed by means of a lid which covers the flatplug-in fuses and the switching devices on the carrier plate.

A method of producing and installing the straps for a central circuitarrangement according to the invention is characterized in that, independence on the intended placement of the straps on the distributorplate, a computer controlled automatic apparatus initially determinesthe length and height of the straps, then bends the straps accordinglyand thereafter mounts them on the distributor plate and laser welds orsolders them. This method ensures fully automatic production of thedistributor plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The idea on which the invention is based will be described in greaterdetail below with reference to several embodiments that are illustratedin the drawing figures. It is shown in:

FIG. 1, a side view of the central circuit arrangement, seen partiallyin section;

FIG. 2, a perspective illustration of the association of the individualcomponents of the central circuit arrangement according to FIG. 1 exceptfor the housing lid;

FIG. 3, a view, to an enlarged scale, of the distributor plate of thecentral circuit arrangement according to FIG. 1 seen in the direction ofarrow III;

FIG. 4, a partial view of the distributor plate of FIG. 3 seen in thedirection of arrow IV in which, for the sake of clarity, the straps areshown in dash-dot lines;

FIG. 5, a partial view of the distributor plate of FIG. 3 seen in thedirection of arrow V;

FIG. 6, a detail view, to an enlarged scale, of a strap of thedistributor plate of FIG. 3;

FIG. 7, a sectional view seen along line VII--VII of the strap of FIG.6;

FIG. 8, an alternative embodiment of the strap according to FIG. 6;

FIG. 9, a view of the strap of FIG. 8 in the direction of arrow IX;

FIG. 10, an alternative embodiment of the central

circuit arrangement of FIG. 2;

FIG. 11, a view, to an enlarged scale, of the distributor plate of thecentral circuit arrangement according to FIG. 10 in the direction ofarrow XI;

FIG. 12, a partial view of the distributor plate of FIG. 11 in thedirection of arrow XII;

FIG. 13, a partial view of the distributor plate of FIG. 11 in thedirection of arrow XIII;

FIG. 14, an enlarged view of the detail "XIV" of FIG. 13;

FIG. 15, an alternative embodiment, to an enlarged scale, of a contactsocket for a distributor plate according to FIG. 12;

FIG. 16, a sectional view of the illustration of FIG. 15, seen alongline XVI--XVI;

FIG. 17, a further alternative embodiment of a contact socket;

FIG. 18, another alternative embodiment of a contact socket;

FIG. 19, a further alternative embodiment of the contact socket as atubular rivet; and

FIG. 20, a sectional view along line XX--XX of the illustrationaccording to FIG. 19.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The central circuit arrangement 1 intended for installation in a motorvehicle is configured in such a way that a large number of electricalcontrol lines and circuits for loads, such as lights, windshield wipers,blinkers, rear window heater, interior heater, mirror heater, solenoidsand the like can be centrally combined by means of plug-in connections.The central circuit arrangement 1 includes a housing 2 made of plasticwhich can be fastened by way of laterally projecting flanges 3 equippedwith passage bores 4 to a holding member which is not shown in detail.Plain connectors 6 project from the underside of the bottom 5 of housing2 and can be connected to wiring harnesses that are provided withplug-in connectors. A collar 7 shaped to bottom 5 surrounds plainconnectors 6 which are connected through bottom 5 to a flat printedcircuit board 8 resting on the interior of bottom 5 in the form of apressed screen. A stack composed of a lower insulating plate 9, anelectrical distributor plate 10, an upper insulating plate 11 and anupper flat printed circuit board 12 in the form of a pressed screen isdisposed on top of flat printed circuit board 8. Altogether they form aplate-like layered conductor packet 13. Above conductor packet 13, acarrier plate 14 equipped With slot recesses 15 is inserted into housing2, with plug-in sockets 16 being disposed below these recesses on theupper flat printed circuit board 12. On the upper face of carrier plate14 there are disposed plug-in components, such as electrical flatplug-in fuses 17 and switching devices 18 including a relay. The plug-inportions of these components pass through slot recesses 15 into plug-insockets 16. A lid 20 fastened to housing 2 be means of snap connections19 extends over flat plug-in fuses 17 and switching devices 18.

On the upper side of distributor plate 10 which is disposed between thelower insulating plate 9 and the upper insulating plate 11, threemutually parallel, continuous pin strips 21 are disposed along thelongitudinal edge of the plate. Their pins 22, which are arranged in arow, pass through respective recesses 23 in insulating plates 9 and Iland contact either the associated terminals 24 of the lower flat printedcircuit board 8 or of the upper flat printed circuit board 12. On theunderside of distributor plate 10, each pin 22 of each pin strip 21 issoldered to a conductor path 25 having at least one terminal 26.Moreover, a plurality of separate conductor path 2 having at least twoterminals 28 are disposed on the underside of distributor plate 10. Incorrespondence with the required circuitry, certain terminals 26, 28 ofdistributor plate 10 are connected with one another by way of straps 29which are coated with an insulating lacquer. In order to ensure that thestraps 29 cross over one another without contact, straps 29 havecorrespondingly different heights. If other circuits are now to beconnected, it is merely necessary to arrange straps 29 in acorrespondingly different manner on distributor plate 10. Thus, theselective attachment of straps 29 provides for the realization of alarge number of the most varied circuits.

Each strap 29 includes a base member 30 from whose end branches off aplug-in member 31. Base member 30 of strap 29 may be bent so as toproduce certain connection paths in different planes. Each plug-inmember 31 of a strap 29 is provided with a pinched section 32 whoseunderside is spaced from the free end of plug-in member 31 at a distancewhich is slightly larger than the thickness of distributor plate 10.Thus the insertion depth of straps 29 in terminals 26 and 28 ofdistributor plate 10 is fixed in a simple manner, thus considerablyfacilitating their soldering to conductor paths 25, 27 of distributorplate 10.

In the alternative embodiment of the central circuit arrangement shownin FIG. 10, three mutually parallel, continuous rows of pins 40 aredisposed on the upper face of distributor plate 10 along itslongitudinal edge. Pins 22 of these rows contact either the associatedterminals 24 of the lower flat printed circuit board 8 or of the upperflat printed circuit board 12 through respective recesses 23 ininsulating plates 9 and 11. Each pin 22 of each row of pins 40 isinserted into a contact socket 42 disposed in a correspondingperforation 41 in distributor plate 10 and is laser welded to thiscontact socket, with passage bore 43 of contact socket 42 having atleast one further free region for accommodating the free end of a strap29. Moreover, a plurality of free perforations 41 are made indistributor plate 10 into which can be inserted, if required, contactsockets 42 whose passage bores 43 are able to accommodate at least twofree ends of two straps 29. According to the required circuitry, contactsockets 42 of distributor plate 10 are connected with one another by wayof straps 29. There straps 29 are laser welded to one another or to thecontact socket 42 or one strap 29 is welded to a pin 22 in a row of pins40, depending on the particular case of use.

The contact sockets 42 of distributor plate 10 depicted in FIGS. 11 to18 are each composed of a sleeve 44 to which is shaped at one end acontinuous external flange 45. Sleeve 44 is inserted in a press fit intothe associated perforation 41 of distributor plate 10, with flange 45resting on the upper face of distributor plate 10. The end of the sleevefacing away from flange 45 projects slightly beyond the underside ofdistributor plate 10. The straps 29 or the pin 22 of a row of pins 40received by sleeve 44 extend slightly beyond the end of sleeve 44 facingaway from flange 45. This permits favorable laser welding between theparts to be connected. Sleeve 44 of contact socket 42 is provided withcontinuous constrictions 46 between which the free ends of straps 29,which have a circular cross section, and possibly a pin 22 of a row ofpins 40 are disposed. In the contact sockets 42 of FIGS. 11 to 14,sleeve 44 is provided with three mutually 120°. offset constrictions 46,with the dimensions of sleeve 44 being such that, in spite of theinsertion of straps 29 or a pin 22 of a row of pins 40 into passage bore43, the central region of passage bore 43 between constrictions 46 ofsleeve 44 remains free, that is, the components inserted into sleeve 44do not contact one another. Therefore it is necessary to perform laserwelding between each inserted component and contact socket 42. Incontrast thereto, the contact socket 42 shown in FIGS. 15 and 16, whichcorresponds in its configuration to contact sockets 42 of FIGS. 11 to14, has such dimensions that the straps 29 inserted therein contact oneanother laterally. Thus only two laser welding locations are requiredbetween the contacting straps 29.

The alternative contact socket 42 shown in FIG. 17 accommodates only twostraps 29 which laterally contact one another in the region of thefacing constrictions 46 of sleeve 44 and are here laser welded together.The alternative contact socket 42 depicted in FIG. 18 is suitable forthe accommodation of four straps 29. Sleeve 44 of this contact socket 42is provided with four constrictions 46 which are arranged at a mutual90° offset and between which lie the straps 29 in lateral contact withone another. In this case, three laser weld locations are requiredbetween straps 29.

In the alternative contact socket 42 shown in FIGS. 19 and 20, thelatter is configured as a tubular rivet 47. In dependence on theinterior diameter of tubular rivet 47, two or more laterally contactingstraps 29 can be inserted thereinto. Straps 29 are here laser welded toone another at their respective points of contact. When inserted into anassociated perforation 41 of distributor plate 10, the head 48 oftubular rivet 47 is supported o the upper side of distributor plate 10,while its base 49 is caulked into the underside of distributor plate 10by way of three projections 50 which are spaced at 120°. relative to oneanother. Thus tubular rivet 47 is given a secure seat in distributorplate 10.

Moreover, after being equipped and laser welded, distributor plate 10 isadditionally soldered to provide for further protection for thecircuits.

The above drawing description clarifies the details of the particularlysimple and easily manipulated construction of the central circuitarrangement which, in spite of its simplicity, has also proven to beextremely variable.

We claim:
 1. A central circuit arrangement for motor vehicles for thecentral connection of electrical components, such as fuses (-7),switching devices (18), wiring harnesses, electronic controls forelectrical loads and the like and including a plate-like layeredconductor packet (13) which is composed of flat printed circuit boards(8, 12) that are arranged on top of one another in different planes andare separated from one another by insulating plates (9, 11),characterized in that an electrical distributor plate (10) with attachedpin strips (21) for contacting the flat printed circuit boards (8, 12)adjacent to the insulating plates (9, 11) is disposed between twoadjacent insulating plates (9, 11), with each pin (22) of each pin strip(21) having an associated conductor path (25) and a free terminal (26);a plurality of further, separate conductor paths (27) having at leasttwo terminals (28) are provided on the distributor plate (10); and theterminals (26, 28) of the conductor paths (25, 27) can be selectivelyconnected by way of straps (29) which, if required, are configured tohave different heights.
 2. A central circuit arrangement according toclaim 1, characterized in that the terminals (26, 28) of the conductorpaths (25, 27) of the distributor plate (10) are selectively connectablewith the terminals (24) of the insulated, superposed, flat printedcircuit boards (8, 12) by way of straps (29) that laterally project fromthe conductor packet (13).
 3. A central circuit arrangement according toclaim 1 characterized in that the straps (29) are coated with aninsulating lacquer.
 4. A central circuit arrangement according to claim1 characterized in that each strap (29) includes two plug-in portions(31) which are angled off from a base portion (30) and are provided witha pinched region (32), with the distance of the pinched region (32) fromthe free end of each plug-in portion (31) being slightly larger than thethickness of the distributor plate (10) or the flat printed circuitboards (8, 12).
 5. A central circuit arrangement according to claim 1characterized in that the base portion (30) of the straps (29) is bentinto different planes.
 6. A central circuit arrangement according toclaim 1 characterized in that the pin strips (21) are replaced by rowsof pins (40) and the conductor paths (25, 27) and their free terminals(26, 28) are replaced by contact sockets (42) that are inserted intocorresponding perforations (41) in the distributor plate (10), with thepassage bore (43) of each contact socket receiving the free ends of aplurality of associated straps (29) or the pin (22) of a row of pins(40) as well as the free end of an associated strap (29) or the freeends of a plurality of associated straps, respectively.
 7. A centralcircuit arrangement according to claim 1 characterized in that eachcontact socket (42) is composed of a sleeve (44) provided with acontinuous flange (45) at its end, with the sleeve being inserted in apress fit into the perforation (41) of the distributor plate (10) andits flange (45) resting on the upper face of the distributor plate (10).8. A central circuit arrangement according to claim 1 characterized inthat the sleeve (44) of the contact socket (42) is provided withconstrictions (46) between which are disposed the free ends of thestraps (29) and, if required, the pin (22) of a row of pins (40).
 9. Acentral circuit arrangement according to claim 1 characterized in thatthe sleeve (44) of the contact socket (42) and its constrictions (46)are configured in such a manner that the free ends of the straps (29)inserted thereinto and, if required, the pin (22) of a row of pins (40)laterally contact one another.
 10. A central circuit arrangementaccording to claim 1 characterized in that each contact socket (42) isconfigured as a tubular rivet (47) which accommodates the inserted endsof the straps (29) and, if required, the pin (22) of a row of pins (40)in mutual lateral contact.
 11. A central circuit arrangement accordingto claim 1 characterized in that the head (48) of the tubular rivet (47)is supported on the upper face of the distributor plate (10) and thebase (49) of the tubular rivet (47) is caulked together with theunderside of the distributor plate (10) by way of three projections (50)spaced at 120° from one another.
 12. A central circuit arrangementaccording to claim 1 characterized in that components, such asresistors, capacitors, transistors, microprocessors, of the electroniccontrols for the various electrical loads of the motor vehicle aredisposed on the distributor plate (10) separated from the flat plug-infuses (17) and switching devices (18) disposed on a carrier plate (14)associated with the upper flat printed circuit board (12) of theconductor packet (13) and are connected with terminals of thedistributor plate (10) by way of conductor paths.
 13. A central circuitarrangement according to claim 1 characterized in that the electroniccontrols for the various electrical loads of the motor vehicle arecentrally combined on the distributor plate (10) in a microcomputerwhich includes at least one microprocessor in the form of an electroniccomputer and at least one program memory as well as at least oneinput/output unit and associated peripherals.
 14. A central circuitarrangement according to claim 1 characterized in that plain connectors(6) extending through the bottom (5) of a housing (2) accommodating theconductor packet (13) and the carrier plate (14) and being delimited bya collar (7) formed at the housing bottom (5) are disposed at the lowerflat printed circuit board (8) of the conductor packet (13) for theconnection of wiring harnesses.
 15. A central circuit arrangementaccording to claim 1 characterized in that the housing (2) is closed bymeans of a lid (20) which extends over the flat plug-in fuses (17) andthe switching devices (18) on the carrier plate (14).
 16. A method ofproducing and installing the straps for a central circuit arrangementaccording to claim 1 characterized in that, in dependence on theintended placement of the straps (29) on the distributor plate (10), thelength and height of the straps are initially determined by means of acomputer controlled automatic apparatus, then the straps are bentaccordingly and thereafter they are installed on the distributor plate(10) and laser welded and/or soldered.